An anti-smoking drug to enable kick off the habit was found to be safe from previously thought side-effects such as risk of heart attacks and depression, said a new study, virtually endorsing the not very popular medical intervention for smokers.
The drug — varenicline or popular as Champix or Chantix, was almost a decade-old but several studies in the past came up with empirical proof that the drug leads to heart diseaes and results in depression and related diseases.
The new research said it has failed to find any evidence about mental illness triggered by the drug and ruled out the popular apprehension that it is not good for smokers.
To arrive at the new finding, a team of researchers looked at anonymous health information from 150,000 smokers across England, who had been prescribed either varenicline or another anti-smoking drug called bupropion to help them quit, or had used nicotine replacement therapy – such as patches, chewing gum or lozenges.
They were tracked for six months and it was found varenicline or buproprion have no side-effects like suffering a heart attack than those using nicotine replacement therapy. Even the risk of depression or self-harm is ruled out, certified the researchers.
“Smokers typically lose three months of life expectancy for every year of continued smoking. Our research supports the use of varenicline as an effective and safe tool to help people quit,” said Daniel Kotz, from the Heinrich-Heine-University Dusseldorf, Germany.
“On the basis of our extensive analysis, we believe it is highly unlikely that varenicline has any significant adverse effects on cardiac or mental health,” said Aziz Sheikh of the University of Edinburgh’s Centre for Medical Informatics.
“Regulators such as the United States Food and Drug Administration (FDA) should review its safety warning in relation to varenicline as this may be unnecessarily limiting access to this effective smoking cessation aid,” Sheikh said.
Researchers at Maastricht University in Netherlands, University College London in UK, and Harvard Medical School in US, were also part of the study, which was published in The Lancet Respiratory Medicine.
Varenicline is sold with the trade name Chantix in the USA and Champix in Canada, Europe and other countries, marketed by Pfizer, usually in the form of varenicline tartrate to treat nicotine addiction.
Adverse effects include nausea that occurs commonly in people taking varenicline. Other less common side effects include headache, difficulty sleeping, and abnormal dreams. Rare side effects reported by people taking varenicline compared to placebo include change in taste, vomiting, abdominal pain, flatulence, and constipation.
In a recent meta-analysis paper by Leung and others, it has been estimated that for every five subjects taking varenicline at maintenance doses, there will be an event of nausea, and for every 24 and 35 treated subjects, there will be an event of constipation and flatulence respectively. Gastrointestinal side-effects lead to discontinuation of the drug in 2% to 8% of people using varenicline.
In November 2007, the US FDA announced it had received reports of thoughts of suicide and occasional suicidal behavior, erratic behavior, and drowsiness among people using varenicline for smoking cessation. Since July 1, 2009, the US FDA has required varenicline to carry a black box warning that the drug should be stopped if any of these symptoms are experienced.
TIts warning says varenicline “has been demonstrated to increase the likelihood of abstinence from smoking for as long as one year compared to treatment with placebo.” and that “the health benefits of quitting smoking are immediate and substantial.”
While a 2014 systematic review did not find evidence of an increased suicide risk, a literature review concluded that varenicline could worsen psychiatric symptoms in people with depression.
In June 2011, the US FDA issued another safety warning that varenicline may be associated with “a small, increased risk of certain cardiovascular adverse events in people who have cardiovascular disease.”
Now that the new study negates all these findings, we may expect more researchers coming out with more evidence on its side-effects and the debate goes on as long as the funding for research continues.